NEW YORK (AP) — The Nielsen company, which has long measured viewership of television programs, now says it has a way to collect and widely spread details about how many people watch programming produced by streaming services like Netflix and Amazon.

Nielsen announced its new service on Wednesday and said that eight television networks and studios, including ABC and NBC, have subscribed to it.

Even with Amazon's "The Handmaid's Tale" winning an Emmy for best drama last month, the number of people who actually watch the program has remained a mystery. Since 2014, Nielsen has been able to count viewership of streamed programs but reported it only to the companies that stream them. The companies, led by industry behemoth Netflix, have largely kept that information a secret.

Now, Nielsen will be able to measure viewership of streamed programs through an audio signature that does not require any action by the programmers to activate it, said Brian Fuhrer, Nielsen's senior vice president of product leadership.

Clients like ABC and NBC will be able to know how many people are watching "House of Cards," for example, and have no reason to keep that information private.

"When people start analyzing this, they're going to be quite surprised at the size of the audience these programs are commanding," Fuhrer said.

Between 12 and 13 percent of television consumption now consists of streamed programs, he said. Half of that are shows on Netflix.

When Netflix made eight episodes of its series "Marvel's The Defenders" available on the same day in August, all of them landed among the 20 most-watched television programs for the week among viewers in the prized 18-to-49-year-old demographic, Nielsen said. The remake "Fuller House" has also had strong numbers.

The research company will be able to measure the impact of binge-watching, too. When a company like Netflix releases a season's worth of episodes on a single day, that show's fans watch an average of four and a half episodes in a day, Nielsen said.

People will also learn demographic information on a show's audience, like which programs are more appealing to young people.

A Netflix representative declined comment on the new service.

So far, Nielsen says it can only measure streaming viewership on television, and not on mobile devices.

Nielsen, in recent years, has begun systematically measuring how many people watch regular television shows on a time-delayed basis, instead of on the same night they are broadcast. That gives a fuller view of the rapidly-changing ways in which experience TV, and the streaming numbers will make that picture even clearer. The numbers are eagerly sought by advertisers who want to know how many people are being exposed to their products.

The extent to which Nielsen will make this information available to the public is unknown, or if the company will incorporate the figures in its weekly release of top programs.